The present invention relates to apparatus and a process for improving the fuel efficiency of internal combustion engines. More specifically, the invention is concerned with improved fuel delivery systems for controlling the mix of a vaporized fuel, such as gasoline, with a flow of air so as to produce a high efficiency fuel/air mixture having improved burning characteristics in present day engines which utilize such fuels.
It is known in the art to modify fuel delivery systems for standard internal combustion engines to provide for a vaporization of the fuel and a delivery of fuel vapor to either a standard carburetor or to a single air intake associated with an intake manifold of the engine. Representative patents which disclose such modifications include, for example, U.S. Pat. Nos. 3,286,703; 3,738,334; 3,763,838; 3,800,533; and 3,886,919. As also disclosed in the aforesaid patents, it is known to provide for relatively simple valves and equivalent regulating devices for regulating fuel and/or air delivery to the combustion zone of such modified engines. These prior art efforts have noted, in some cases, that the use of vaporized gasoline in combination with ambient air results in improved burning characteristics of the fuel/air mixture to the extent of providing increased mileage with a given quantity of fuel and a reduction in unwanted emissions from the combustion process.
The present invention shares with the prior art an interest in providing greater efficiencies in fuel consumption and fuel burning characteristics in internal combustion engines which are typically installed in passenger cars and other motor vehicles. The invention also utilizes prior art concepts which suggest a vaporization of fuel prior to mixing with air as a basic approach to optimizing fuel efficiency in a combustion process. However, it is believed that even greater efficiencies can be obtained beyond those suggested by the prior art by following my present teachings which provide for an improved regulation and mixing of fuel vapor with a flow of heated air being drawn into the combustion zone of an internal combustion engine.
In accordance with the basic process of this invention, a liquid fuel, such as gasoline, is vaporized in accordance with known techniques to produce a fuel vapor. Separately, a flow of air is preheated and delivered to a mixing zone where the pre-heated air can be combined with the heated fuel vapor. This process includes a step of diverting the flow of pre-heated air around a mixing cone element so as to create a zone of turbulence downstream from the position of the mixing cone element, and it is in this zone of turbulence that the fuel vapor is introduced into the pre-heated air stream to produce a high efficiency fuel/air mixture. This mixture is then delivered to the combustion zones of an associated engine.
In order to carry out the basic process of this invention, an improved mixing chamber has been devised for regulating the flow of fuel vapor to the mixing zone and for optimizing the introduction of the fuel vapor into a flow of air which is admitted to the mixing zone.
Basic structural features of the improved mixing chamber include a cylindrical housing for defining a mixing zone in its interior. The housing has a major inlet for admitting air to the mixing zone, a plurality of ports for introducing fuel vapor into the mixing zone, and a major outlet for discharging a fuel/air mixture to combustion zones of an associated internal combustion engine. The housing is provided with a regulating assembly fitted therein for relative movement between limit positions which provide for a sequential opening and closing of the plurality of ports formed in the housing. In this manner, a control of the regulating assembly can effect greater or lesser rates of delivery of fuel vapor into the mixing zone, and this control can be carried out with linkage means operatively connected between the regulating assembly and a standard throttle control for the associated internal combustion engine.
The regulating assembly is further designed and constructed to support a mixing cone element in a position which is on a central axis of the mixing chamber (and therefore on a central axis of an air stream moving through the housing) so as to divert an incoming air stream around the mixing cone element in a way that creates a turbulent condition downstream from the position of the mixing cone element. Additionally, means are provided for delivering the fuel vapor to the downstream side of the mixing cone element so that the vapor is, in effect, introduced into a central core region of the turbulent zone which has been created. Farther downstream from the position of the mixing cone element is the major outlet for the housing, and the diameter of this major outlet is somewhat smaller than the diameter of the mixing cone itself so that mixed fuel vapor and air are constricted in their passage from the mixing chamber of the housing to an intake manifold or other plenum associated with an internal combustion engine to which the fuel delivery system is applied.
As a result of the specific improvements of the present invention, I have found that the standard carburetor of an internal combustion engine can be completely eliminated and the improved mixing chamber of my invention substituted therefor. With such a substitution, I have experienced greatly improved fuel consumption characteristics with a standard internal combustion engine in an automobile. The improved fuel consumption characteristics are of such a magnitude it can be theorized that burning efficiencies and completeness of combustion have been greatly improved over any of the suggested arrangements of the prior art known to me.
In a specific application of my invention to an existing engine of the V-block type, I mounted a fuel conduit in heat exchange relationship with an exhaust manifold in one side of the V-block for converting a flow of liquid gasoline into a flow of vapor gasoline. On the opposite side of the V-block engine, I mounted an air conduit in heat exchange relationship with the exhaust manifold on that side to provide for a pre-heating of a flow of air to be supplied to the engine. My improved mixing chamber was mounted so as to receive gasoline vapor from the fuel conduit and the stream of heated air from the air conduit, and my improved regulating assembly was contained within the mixing chamber for regulating the flow of gasoline vapor into the air stream. The regulating assembly included a mixing cone element for creating a zone turbulence into which the gasoline vapor was introduced.
In addition to the basic structural relationships just described, my fuel delivery system also included a needle valve assembly in the conduit which conducted gasoline vapor to the mixing chamber. This needle valve assembly served to provide a separate control of gasoline vapor flow to the mixing chamber and could be used to completely close off the fuel conduit upon shutting down the engine. Although the needle valve could be operated by automatic or semi-automatic means, my own preference was to provide for a manual control of the needle valve assembly from within the driver's compartment of the automobile so that optimum vapor flow rates could be achieved for various running conditions that are experienced with different types of driving or with an engine which is not fully warmed up or one which has been operating for a sustained period of time.
These and other features and advantages of the present invention will become apparent in the more detailed discussions which follow, and in those discussions reference will be made to the accompanying drawings as briefly described below.